JP2017228109A - Electronic apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To correctly discriminate displacement states of a first housing and a second housing by a simple constitution.SOLUTION: An electronic apparatus 100 includes: a first housing 10 and a second housing 20 arranged so as to be displaced in a first state (left figure) where first main surfaces 10a, 20a are opposed to each other and a second state (right figure) where second main surfaces 10b, 20b are opposed to each other; a magnetic detection unit 40 arranged in the first housing 10; a magnet 50 arranged in the second housing 20; and a control unit (not shown) for discriminating the first state and the second state on the basis of an output from the magnetic detection unit 40. The magnet 50 is arranged so that a magnetization direction is orthogonal to the first main surface 20a and the second main surface 20b of the second housing 20. The magnetic detection unit 40 includes a first magnetic sensor A and a second magnetic sensor B arranged along normal directions of the first main surface 10a and the second main surface 10b of the first housing 10.SELECTED DRAWING: Figure 2

Description

  The present invention relates to electronic devices such as smartphones, tablets, and notebook PCs.

  FIG. 16 is a schematic diagram showing a conventional example of an electronic device. The electronic device 200 according to the conventional example includes a first state in which the upper surface of the main body 210 is covered with the cover 220 (left in the drawing) and a second state in which the lower surface of the main body 210 is covered with the cover 220 (right in the drawing). As a means for determining the magnetic sensor IC 230 (for example, a bipolar detection Hall IC) built in the main body 210 and a magnet 240 built in the cover 220. The magnet 240 is arranged so that its magnetization direction (= magnetization direction) is parallel to the main surface of the cover 220.

  On the other hand, the magnetic sensor IC 230 is arranged such that its package main surface (upper surface and lower surface) is parallel to the main surface of the main body 210, and a magnetic field (= Detect vertical magnetic field. Referring to this figure, in the first state (left figure), a vertical magnetic field from the upper surface to the lower surface of the package is detected by the magnetic sensor IC 230. On the other hand, in the second state (right in the figure), a vertical magnetic field from the lower surface to the upper surface of the package is detected by the magnetic sensor IC 230. Therefore, based on whether the output polarity of the magnetic sensor IC 230 is positive or negative, the first state (left in the figure) and the second state (right in the figure) can be distinguished.

  FIG. 17 is a schematic diagram for defining the amount of displacement (X, Y, Z) of the magnetic sensor IC 230 with respect to the magnet 240. As shown in the figure, the displacement amount X in the left-right direction of the paper surface, the displacement amount Y in the front-rear direction of the paper surface, and the displacement amount Z in the vertical direction of the paper surface are respectively set at the origin O (0, 0, 0). As for the positive and negative polarities of the displacement amounts (X, Y, Z), the right direction on the paper surface, the back direction on the paper surface, and the downward direction on the paper surface are the positive directions.

  FIG. 18 is a correlation diagram between the displacement amounts X and Z (displacement amount Y = 0) of the magnetic sensor IC 230 and the vertical magnetic field. In this figure, the horizontal axis is the displacement amount X (mm), and the vertical axis is the displacement amount Z (mm). Also, as a precondition of this figure, the magnet 240 has a thin plate shape of 7.5 mm in length (left and right direction on paper) × 7.5 mm in width (front and rear direction on paper) × 0.5 mm in height (up and down direction on paper). It is assumed that the residual magnetic flux density is 1400 mT.

  Further, the gradation area in the figure is an area where the vertical magnetic field is 5 mT or more, and indicates that the vertical magnetic field is larger as the gradation density is higher. In order to correctly determine the displacement state of the main body 210 and the cover 220 from the direction of the vertical magnetic field detected by the magnetic sensor IC 230, in the first state or the second state described above, the magnetic sensor IC 230 has a gradation area in the figure. It is necessary to position the magnetic sensor IC 230 and the magnet 240 in advance so that the magnetic sensor IC 230 and the magnet 240 are positioned within the inside (= a position shifted obliquely from the front surface of the magnetic pole of the magnet 240).

  As an example of the related art related to the above, Patent Document 1 can be cited.

JP2015-119470A

  However, in the above-described conventional electronic device 200, the magnetic field at a position shifted in the oblique direction from the front side of the magnetic pole of the magnet 240 is only about half of the magnetic field at the front side of the magnetic pole at the maximum. It will attenuate.

  For this reason, in the above-described conventional electronic device 200, the detection distance of the magnetic sensor IC 230 (= the distance at which a vertical magnetic field can be correctly detected) is short and vulnerable to noise. = State determination error).

  In the electronic device 200 of the conventional example, when the displacement amount X of the magnetic sensor IC 230 changes from positive to negative, the direction of the vertical magnetic field applied to the magnetic sensor IC 230 is reversed. There was a risk of misdetecting the displacement state.

  In addition, in the prior art of patent document 1, since it was necessary to incline the magnet provided in a cover diagonally with respect to the main body surface, the mounting was very difficult and there existed a subject that the thickness of a cover became large. .

  In view of the above-described problems found by the inventors of the present application, the invention disclosed in this specification is an electronic device that can correctly determine the displacement state of the first housing and the second housing with a simple configuration. The purpose is to provide equipment.

  The electronic device disclosed in the present specification is provided so as to be displaceable between a first state in which the first main surfaces face each other and a second state in which the respective second main surfaces face each other. The first state based on the first casing and the second casing, the magnetic detection unit provided in the first casing, the magnet provided in the second casing, and the output of the magnetic detection unit And a controller for discriminating the second state, and the magnet is disposed so that the magnetization direction thereof is orthogonal to the first main surface and the second main surface of the second casing, The magnetic detection unit includes a first magnetic sensor and a second magnetic sensor (first configuration) disposed along the normal direction of the first main surface and the second main surface of the first housing. Has been.

  In the electronic apparatus having the first configuration, the control unit compares the outputs of the first magnetic sensor and the second magnetic sensor to determine the first state and the second state ( The second configuration may be used.

  In the electronic device having the first or second configuration, the first magnetic sensor and the second magnetic sensor are both integrated in a single magnetic sensor IC (third configuration). It is good to.

  In the electronic apparatus having the first or second configuration, the first magnetic sensor is integrated in a first magnetic sensor IC, and the second magnetic sensor is integrated in a second magnetic sensor IC. The first magnetic sensor IC is mounted on the first mounting surface of the printed board, and the second magnetic sensor IC is mounted on the second mounting surface of the printed board (fourth). It is also possible to use

  Further, in the electronic apparatus having the first configuration, the magnetic detection unit includes a third magnetic sensor disposed along a normal direction of the first main surface and the second main surface of the first housing, and The third magnetic sensor further includes a fourth magnetic sensor, the third magnetic sensor is disposed on the same plane as the first magnetic sensor, and the fourth magnetic sensor is disposed on the same plane as the second magnetic sensor. (5th configuration).

  In the electronic apparatus having the fifth configuration, the control unit may include a differential output of the first magnetic sensor and the fourth magnetic sensor and a differential output of the second magnetic sensor and the third magnetic sensor. It is preferable to adopt a configuration (sixth configuration) in which the first state and the second state are determined by determining whether the absolute value is larger.

  In the electronic device having the fifth or sixth configuration, each of the first magnetic sensor, the second magnetic sensor, the third magnetic sensor, and the fourth magnetic sensor is a single magnetic sensor. A configuration integrated with the IC (seventh configuration) is preferable.

  In the electronic device having the fifth or sixth configuration, the first magnetic sensor and the second magnetic sensor are both integrated in a first magnetic sensor IC, and the third magnetic sensor and the second magnetic sensor are integrated with each other. The fourth magnetic sensor is integrated in the second magnetic sensor IC, and the first magnetic sensor IC and the second magnetic sensor IC are both mounted on the same mounting surface of the printed circuit board ( An eighth configuration may be used.

  Further, the electronic device having any one of the first to eighth configurations is provided on the first main surface of the first casing and on the first main surface of the second casing. An operation unit, wherein the control unit sets the electronic device to a dormant state when the first state is determined, and sets the operation unit to an invalid state when the second state is determined ( The ninth configuration may be used.

  In the electronic device having any one of the first to ninth configurations, the first housing and the second housing may be configured to be detachable from each other (tenth configuration).

  According to the invention disclosed in the present specification, it is possible to provide an electronic device that can correctly determine the displacement state of the first housing and the second housing with a simple configuration.

External view of electronic equipment Schematic diagram showing the first embodiment of the electronic device Schematic diagram for defining the amount of displacement of the magnetic sensor IC relative to the magnet Correlation diagram between displacement of magnetic sensor IC and vertical magnetic field Block diagram showing a configuration example of a magnetic sensor IC Schematic diagram showing a second embodiment of the electronic device Schematic diagram showing a third embodiment of the electronic device Schematic diagram showing the output state in the first state (X> 0) Schematic diagram showing the output state in the first state (X <0) Schematic diagram showing the output state in the second state (X> 0) Schematic diagram showing the output state in the second state (X <0) Schematic diagram for defining the amount of displacement of the magnetic sensor IC relative to the magnet Correlation diagram between X and A / B and max (A / D, C / B) Correlation diagram of X and AB and max (AD, CB) Schematic diagram showing a fourth embodiment of the electronic device Schematic diagram showing a conventional example of electronic equipment Schematic diagram for defining the amount of displacement of the magnetic sensor IC relative to the magnet Correlation diagram between displacement of magnetic sensor IC and vertical magnetic field

<Electronic equipment>
FIG. 1 is an external view of an electronic device. The electronic device 100 of this configuration example is a hybrid portable terminal (so-called 2 in 1 PC) that can be used as a notebook PC or a tablet, and includes a main body 10, a cover 20, and a connecting portion 30.

  The main body 10 corresponds to a first housing of the electronic device 100, and includes a first main surface 10a and a second main surface 10b. The first main surface 10a is provided with a display unit (liquid crystal display or organic EL display) having a touch panel function.

  The cover 20 corresponds to a second housing of the electronic device 100 and includes a first main surface 20a and a second main surface 20b. The first main surface 20a is provided with an operation unit (such as a keyboard) for receiving a user operation.

  As shown by arrows a and b in the figure, the connecting portion 30 supports the cover 20 so as to be rotatable (openable and closable) by approximately 360 ° with respect to the main body 10 with itself as a rotation shaft (opening / closing shaft). . In the example of this figure, the connecting portion 30 is depicted as a hinge member independent of the main body 10 and the cover 20, but the configuration of the connecting portion 30 is not limited to this, and the connecting portion 30 is a part of the cover 20. It is good. The main body 10 and the cover 20 may be detachable.

<Displacement state>
The main body 10 and the cover 20 are in a displacement state in a first state when the electronic device 100 is not used (upper part in the figure), and in a second state when the electronic device 100 is used as a tablet (lower part in the figure). ) And a third state (the middle stage in the figure) when the electronic device 100 is used as a notebook PC.

  The first state (the upper part of the figure) indicates a state in which the cover 20 is closed so as to cover the front surface (= first main surface 10a) of the main body 10. In the first state, the main body 10 and the cover 20 are parallel to each other, and the first main surfaces 10a and 20a face each other.

  The second state (the lower part of the figure) indicates a state in which the cover 20 is folded on the back surface (= second main surface 10b) side of the main body 10. In the second state, the main body 10 and the cover 20 are parallel to each other, and the second main surfaces 10b and 20b face each other.

  The term “opposing” in this specification is understood not only to indicate a state in which there are no inclusions between the main surfaces facing each other, but also to include a state in which a liquid crystal protective film, a keyboard cover, or the like is interposed. can do.

  In addition, the distance between the main surfaces facing each other is shorter than the distance between the main surfaces not facing each other. Specifically, in the first state where the first main surfaces 10a and 20a face each other, the distance between the first main surfaces is shorter than the distance between the second main surfaces. Conversely, in the second state where the second main surfaces 10b and 20b are opposed to each other, the distance between the second main surfaces is shorter than the distance between the first main surfaces.

  The third state (the middle in the figure) indicates a state where the cover 20 is opened and fixed to an arbitrary angle. That is, it can be understood that the third state is a state in the middle of transition from one of the first state and the second state to the other.

  Note that the electronic device 100 of the present configuration example includes a magnetic sensor and a magnet as means for determining the above-described displacement state, and is particularly characterized by their arrangement and sensor output calculation method. Therefore, in the following, a new configuration for correctly determining the displacement state of the main body 10 and the cover 20 will be proposed by taking a specific embodiment as an example.

<First Embodiment>
FIG. 2 is a schematic diagram illustrating the first embodiment of the electronic device 100. The left side of the figure shows a first state (corresponding to the upper part of FIG. 1) in which the first main surfaces 10a and 20a of the main body 10 and the cover 20 face each other. On the other hand, the right side of the figure shows a second state (corresponding to the lower part of FIG. 1) where the second main surfaces 10b and 20b of the main body 10 and the cover 20 face each other.

  As shown in the figure, the electronic apparatus 100 of the present embodiment includes a magnetic sensor IC 40 (= corresponding to a magnetic detection unit) and a magnet 50 inside the main body 10 and the cover 20.

  The magnetic sensor IC 40 is a semiconductor integrated circuit device in which two magnetic sensors A and B are integrated, and its package main surface (upper surface and lower surface) is relative to the first main surface 10a and the second main surface 10b of the main body 10. It is mounted on the mounting surface of the printed circuit board PCB so as to be parallel.

  The magnetic sensors A and B are arranged in the illustrated order (first order) along the normal direction of the main surface of the package of the magnetic sensor IC 40, that is, along the normal directions of the first main surface 10a and the second main surface 10b of the main body 10. 1 main surface 10a-magnetic sensor A-magnetic sensor B-second main surface 10b), each detecting a magnetic field (= vertical magnetic field) applied perpendicular to the package main surface of the magnetic sensor IC 40. To do. As the magnetic sensors A and B, Hall elements, magnetoresistive elements, and the like can be suitably used.

  The magnet 50 is arranged so that the magnetization direction thereof is orthogonal to the first main surface 20 a and the second main surface 20 b of the cover 20. Referring to this figure, the magnet 50 is disposed such that the N pole faces the first main surface 20a and the S pole faces the second main surface 20b. Therefore, in either the first state (left in the figure) or the second state (right in the figure), a magnetic field from the upper surface to the lower surface of the package is applied to the magnetic sensor IC 40.

  Although not explicitly shown in the figure, the printed circuit board PCB of the main body 10 includes a microcomputer for discriminating between the first state (left in the figure) and the second state (right in the figure) based on the output of the magnetic sensor IC 40. 60 (= corresponding to the control unit, see FIG. 5 described later) is mounted.

  As shown in the figure, in the first state (left of the figure), the distance between the magnetic sensor A and the magnet 50 is shorter than the distance between the magnetic sensor B and the magnet 50, so that the magnetic sensor A is applied. The vertical magnetic field is larger than the vertical magnetic field applied to the magnetic sensor B. Therefore, when the outputs of the magnetic sensors A and B are compared, A> B (or AB> 0).

  On the other hand, in the second state (right in the figure), since the distance between the magnetic sensor B and the magnet 50 is shorter than the distance between the magnetic sensor A and the magnet 50, the perpendicular magnetic field applied to the magnetic sensor B is the magnetic sensor A. It becomes larger than the vertical magnetic field applied to. Therefore, when the outputs of the magnetic sensors A and B are compared, A <B (or A−B <0).

  From the above knowledge, the microcomputer 60 compares the outputs of the magnetic sensors A and B to determine the first state (left in the figure) and the second state (right in the figure). Referring to this figure, the microcomputer 60 determines that it is in the first state (left in the figure) when A> B (or AB> 0), and A <B (or AB <0). ) Is determined as the second state (right in the figure).

  Although not explicitly shown in the figure, in the above-described third state (middle stage in FIG. 1), the main body 10 and the cover 20 are separated from each other, so that no magnetic field is applied to the magnetic sensor IC 40. Therefore, in the microcomputer 60, when the outputs of the magnetic sensors A and B are both lower than the threshold value, or when the total output of the magnetic sensors A and B is lower than the threshold value, the third state (the middle stage in FIG. 1). ).

  As described above, the first state (left in the figure) is a displacement state when the electronic device 100 is not used (see also the upper part of FIG. 1). In view of this, it is desirable for the microcomputer 60 to place the electronic device 100 (at least the display unit) in a dormant state when determining that the microcomputer 60 is in the first state (left in the figure). By performing such control, the power consumption of the electronic device 100 can be suppressed, so that the battery driving time can be extended.

  Further, as described above, the second state (right in the figure) is a displacement state when the electronic device 100 is used as a tablet (see also the lower part of FIG. 1). In view of this, when the microcomputer 60 determines that it is in the second state (right in the figure), it is desirable that the operation unit of the cover 20 be in an invalid state. By performing such control, even if the operation unit is accidentally touched during use as a tablet, an unintended malfunction does not occur.

  FIG. 3 is a schematic diagram for defining the amount of displacement (X, Y, Z) of the magnetic sensor IC 40 (particularly the magnetic sensor A) with respect to the magnet 50 in the electronic device 100 of the first embodiment. As shown in this figure, the displacement amount X in the left-right direction of the paper surface, the displacement amount Y in the front-rear direction of the paper surface, and the displacement amount Z in the vertical direction of the paper surface are respectively set at the origin O (0, 0, 0). As for the positive and negative polarities of the displacement amounts (X, Y, Z), the right direction on the paper surface, the back direction on the paper surface, and the downward direction on the paper surface are the positive directions.

  FIG. 4 is a correlation diagram between the displacement amounts X and Z (displacement amount Y = 0) of the magnetic sensor IC 40 and the vertical magnetic field. In this figure, the horizontal axis is the displacement amount X (mm), and the vertical axis is the displacement amount Z (mm). In addition, as a precondition of this figure, the magnet 50 has a thin plate shape of 7.5 mm in length (paper left-right direction) × 7.5 mm in width (front-back direction on paper) × 0.5 mm in height (up-down direction on paper) It is assumed that the residual magnetic flux density is 1400 mT. That is, the magnet 50 is the same as the conventional magnet 240 (FIG. 16) except that the magnetization direction is different.

  Further, the gradation area in the figure is an area where the vertical magnetic field is 5 mT or more, and indicates that the vertical magnetic field is larger as the gradation density is higher. On the other hand, the broken line area in the figure shows the correlation diagram (FIG. 18) of the conventional example in a superimposed manner for comparison and reference.

  In order to correctly determine the displacement state of the main body 10 and the cover 20 by comparing the outputs of the magnetic sensors A and B, in the first state or the second state, the magnetic sensor IC 40 is in the gradation area in the figure. It is desirable to position each of the magnetic sensor IC 40 and the magnet 50 so as to be within (= the front surface of the magnetic pole of the magnet 50).

  Here, the magnetic field in front of the magnetic pole is larger than the magnetic field at other positions, and is not easily attenuated even if it is slightly away from the magnet 50. Therefore, in the electronic device 100 of the present embodiment, the detection range of the magnetic sensor IC 40 is widened and strong against noise as compared with the conventional example, and therefore malfunction (= state determination error) due to the positional deviation of the cover 20 or the like. It becomes possible to reduce.

  In addition, even if the displacement amount X of the magnetic sensor IC 40 changes from plus to minus due to the displacement of the cover 20 or the like, the direction of the vertical magnetic field applied to the magnetic sensor IC 40 is not reversed. There is no false detection.

<Magnetic sensor IC>
FIG. 5 is a block diagram illustrating a configuration example of the magnetic sensor IC 40. In addition to the magnetic sensors A and B, the magnetic sensor IC 40 of this configuration example includes dynamic offset cancellers 41A and 41B (hereinafter referred to as DOC [dynamic offset canceller] 41A and 41B), amplifiers 42A and 42B, and AD [ Analog-to-digital] converters 43A and 43B, a logic unit 44, an interface unit 45, a regulator 46, a power-on reset unit 47, and an oscillator 48 are integrated.

  Each of the magnetic sensors A and B detects a magnetic field (= vertical magnetic field) applied perpendicular to the package main surface of the magnetic sensor IC 40. The magnetic sensors A and B using Hall elements and magnetoresistive elements can be equivalently expressed as Wheatstone bridge circuits (resistance bridge circuits).

  Each of the DOCs 41A and 41B operates by receiving the supply of the internal power supply voltage VREG, and cancels the offset voltage of the magnetic sensors A and B by switching the driving current directions of the magnetic sensors A and B, so that only a desired signal component is obtained. Sample / hold output.

  The amplifiers 42A and 42B operate by receiving the internal power supply voltage VREG, respectively, and amplify the sample / hold outputs of the DOCs 41A and 41B with a predetermined gain.

  Each of the AD converters 43A and 43B operates by receiving the internal power supply voltage VREG, and converts an analog amplifier output into a digital signal.

  The logic unit 44 operates in response to the supply of the internal power supply voltage VREG, and outputs digital signals input from the AD converters 43A and 43B to the microcomputer 60 via the interface unit 45. The microcomputer 60 determines the first state and the second state described above by comparing the outputs of the magnetic sensors A and B.

The interface unit 45 includes an I ² C bus or an SPI (serial peripheral interface) bus (or both), and performs bidirectional communication between the logic unit 44 and the microcomputer 60.

  The regulator 46 converts the external power supply voltage VDD into a predetermined internal power supply voltage VREG. As the regulator 46, an LDO [low drop-out] regulator having a small circuit scale can be suitably used.

  The power-on reset unit 47 monitors the external power supply voltage VDD or the internal power supply voltage VREG, and performs a power-on reset process for each part of the IC.

  The oscillator 48 operates in response to the supply of the internal power supply voltage VREG, and generates a driving clock signal necessary for the operation of each part of the IC.

Second Embodiment
FIG. 6 is a schematic diagram illustrating the second embodiment of the electronic device 100. The present embodiment is characterized in that the magnetic sensors A and B are distributed and integrated in separate magnetic sensor ICs 40A and 40B while being based on the first embodiment (FIG. 2). Therefore, the same components as those in the first embodiment are denoted by the same reference numerals as those in FIG. 2, and redundant descriptions are omitted. In the following, the characteristic portions of the second embodiment will be mainly described.

  As shown in the figure, the magnetic sensor IC 40A in which the magnetic sensor A is integrated is mounted on the first mounting surface of the printed circuit board PCB. On the other hand, the magnetic sensor IC 40B in which the magnetic sensor B is integrated is mounted on the second mounting surface of the printed circuit board PCB.

  In addition, the magnetic sensor ICs 40A and 40B are arranged on the printed circuit board PCB so that the magnetic sensors A and B integrated therein are aligned along the normal direction of the first main surface 10a and the second main surface 10b of the main body 10, respectively. It is mounted in a position that overlaps on both sides.

  By adopting such a configuration, the distance between sensors (= the distance between the magnetic sensor A and the magnetic sensor B) can be increased as compared with the first embodiment (FIG. 2). Therefore, since the output difference between the magnetic sensors A and B becomes large, it is possible to correctly determine the displacement state of the main body 10 and the cover 20 even if the cover 20 is displaced.

<Third Embodiment>
FIG. 7 is a schematic diagram illustrating a third embodiment of the electronic device 100. This embodiment is based on the first embodiment (FIG. 2), and in addition to the previous magnetic sensors A and B, the magnetic sensors C and D are further integrated in a single magnetic sensor IC 40. It is characterized by the point. Therefore, the same components as those in the first embodiment are denoted by the same reference numerals as those in FIG. 2, and redundant descriptions are omitted. In the following, characteristic portions of the third embodiment will be mainly described.

  The magnetic sensors C and D are the normal directions of the package main surface of the magnetic sensor IC 40 as in the case of the magnetic sensors A and B described above, that is, the method of the first main surface 10 a and the second main surface 10 b of the main body 10. Along the line direction, they are arranged in the order shown (first main surface 10a-magnetic sensor C-magnetic sensor D-second main surface 10b) and applied perpendicularly to the package main surface of the magnetic sensor IC 40. The detected magnetic field (= vertical magnetic field) is detected. The magnetic sensor C is arranged on the same plane as the magnetic sensor A, and the magnetic sensor D is arranged on the same plane as the magnetic sensor B.

  As described above, when the magnetic sensor IC 40 in which the four magnetic sensors A to D are integrated is used, the magnetic sensors provided at the diagonal positions instead of the magnetic sensors A and B (or C and D) arranged in the vertical direction. By comparing the outputs of the sensors A and D (or B and C), the displacement states of the main body 10 and the cover 20 can be more correctly determined. The reason will be described below with specific calculation examples.

  FIG. 8 is a schematic diagram showing an output state when the displacement amount X of the magnetic sensor IC 40 with respect to the magnet 50 is positive (X> 0) in the above-described first state (left side in FIG. 7). In the following description, it is assumed that the outputs of the magnetic sensors A to D are A = 19.86 mT, B = 18.40 mT, C = 18.86 mT, and D = 17.48 mT.

  In this case, A−D = + 2.38 mT (= 19.86 mT−17.48 mT) and CB = + 0.46 mT (= 18.86 mT−18.40 mT). Therefore, | A−D |> | CB |. Therefore, the microcomputer 60 determines the first state and the second state by determining whether the absolute value is larger (here, AD). In the example of this figure, since AD> 0, it is determined that the magnet 50 is positioned on the upper surface side of the magnetic sensor IC 40, that is, the first state (left side in FIG. 7).

  The differential output (= A−D = + 2.38 mT) of the magnetic sensors A and D is larger than the differential output (= A−B = + 1.46 mT) of the magnetic sensors A and B, and the magnetic sensor It is larger than the differential output of C and D (= C−D = + 1.38 mT). In view of this, when determining the displacement state of the main body 10 and the cover 20, rather than comparing the outputs of the magnetic sensors A and B (or C and D) arranged in the vertical direction, the diagonal positions are set. It can be said that it is advantageous to compare the outputs of the magnetic sensors A and D (or B and C) provided.

  FIG. 9 is a schematic diagram showing an output state when X <0 in the first state (left side of FIG. 7). In the following description, it is assumed that A = 18.86 mT, B = 17.48 mT, C = 19.86 mT, and D = 18.40 mT.

  In this case, A−D = + 0.46 mT (= 18.86 mT−18.40 mT) and CB = + 2.38 mT (= 19.86 mT−17.48 mT). Therefore, | A−D | <| CB |. Therefore, the microcomputer 60 determines the first state and the second state by determining whether the absolute value is larger (here, CB). In the example of this figure, since CB> 0, it is determined that the state is the first state (left side in FIG. 7).

  FIG. 10 is a schematic diagram showing an output state when X> 0 in the above-described second state (right side in FIG. 7). In the following description, it is assumed that A = 18.40 mT, B = 19.86 mT, C = 17.48 mT, and D = 18.86 mT.

  In this case, A−D = −0.46 mT (= 18.40 mT-18.86 mT) and CB = −2.38 mT (= 17.48 mT-19.86 mT). Therefore, | A−D | <| C-B | Therefore, the microcomputer 60 determines the first state and the second state by determining whether the absolute value is larger (here, CB). In the example of this figure, since C−B <0, it is determined that the magnet 50 is located on the lower surface side of the magnetic sensor IC 40, that is, the second state (right side in FIG. 7).

  FIG. 11 is a schematic diagram showing an output state when X <0 in the above-described second state (right side of FIG. 7). In the following description, it is assumed that A = 17.48 mT, B = 18.86 mT, C = 18.40 mT, and D = 19.86 mT.

  In this case, A−D = −2.38 mT (= 17.48 mT−19.86 mT) and CB = −0.46 mT (= 18.40 mT−18.86 mT). Therefore, | A−D | > | C-B |. Therefore, the microcomputer 60 determines the first state and the second state by determining whether the absolute value is larger (here, AD). In the example of this figure, since A−D <0, it is determined to be in the second state (right side in FIG. 7).

  As described above, as shown in FIGS. 8 to 11, the microcomputer 60 includes the difference output (= A−D) between the magnetic sensors A and D and the difference output (= C−B) between the magnetic sensors B and C. The first state and the second state are determined by determining whether the absolute value is larger. By adopting such a configuration, it is possible to more correctly determine the displacement state of the main body 10 and the cover 20 than in the first embodiment (FIG. 2).

  Although not explicitly shown in FIGS. 8 to 11, when the outputs of the magnetic sensors A to D are all below the threshold value, or the total output of the magnetic sensors A to D is below the threshold value. It can be determined that the state is the above-described third state (the middle stage in FIG. 1).

  FIG. 12 is a schematic diagram for defining the amount of displacement (X, Y, Z) of the magnetic sensor IC 40 (particularly the magnetic sensor A) relative to the magnet 50 in the electronic device 100 of the third embodiment. As shown in this figure, the displacement amount X in the left-right direction of the paper surface, the displacement amount Y in the front-rear direction of the paper surface, and the displacement amount Z in the vertical direction of the paper surface are respectively set at the origin O (0, 0, 0). As for the positive and negative polarities of the displacement amounts (X, Y, Z), the right direction on the paper surface, the back direction on the paper surface, and the downward direction on the paper surface are the positive directions.

  In addition, the magnetic sensors A and B (or C and D) are formed with a predetermined distance d between the sensors in the vertical direction on the paper surface, and the magnetic sensors A and C (or B and D) are on the left and right surfaces of the paper surface. It is assumed that a predetermined distance w between sensors is formed in the direction.

  FIGS. 13 and 14 are correlation diagrams between the displacement amount X of the magnetic sensor IC 40 and the magnetic field ratios A / B and max (A / D, C / B), respectively, and the displacement amount X of the magnetic sensor IC 40 and the magnetic field difference. It is a correlation diagram with AB and max (AD, CB).

  The magnetic field ratio max (A / D, C / B) is the larger of the magnetic field ratios A / D and C / B. Similarly, the magnetic field difference max (AD, CB) is the larger of the magnetic field differences AD and CB.

  Further, as preconditions of FIGS. 13 and 14, it is assumed that Y = 0 mm, Z = 5.0 mm, d = 0.222 mm, and w = 0.5 mm, and the magnet 50 has a length of 7.5 mm. It is assumed that the sheet has a thin plate shape of (horizontal direction on the paper surface) × 7.5 mm laterally (front-back direction on the paper surface) × 0.5 mm height (vertical direction on the paper surface), and the residual magnetic flux density is 1400 mT.

  As indicated by the broken line in FIG. 13, the magnetic field ratio A / B becomes a maximum value (≈1.1) when X≈0, and decreases as | X | increases. On the other hand, as shown by the solid line in FIG. 13, the magnetic field ratio max (A / D, C / B) becomes a minimum value (≈1.1) when X≈0, and increases as | X | increases. . Therefore, the magnetic field ratio max (A / D, C / B) is always larger than the magnetic field ratio A / B regardless of the displacement amount X.

  Further, as shown by the broken line in FIG. 14, the magnetic field difference AB becomes a maximum value (≈1.5) when X≈0, and decreases as | X | increases. On the other hand, as indicated by the solid line in FIG. 14, the magnetic field difference max (A−D, C−B) becomes a minimum value (≈1.5) when X≈0, and a maximum value when | X | ≈2.5. (≈3.2). When | X |> 2.5, the magnetic field difference max (AD, CB) decreases monotonously, but as shown in this figure, at least | X | <5.0 In this range, the magnetic field difference max (AD, CB) does not fall below the magnetic field difference AB.

  As can be seen from the above knowledge, when the displacement states of the main body 10 and the cover 20 are more correctly determined, the differential outputs (= A) of the magnetic sensors A and D are compared with the comparison of the outputs of the magnetic sensors A and B. -D) and the difference output (= C-B) of the magnetic sensors B and C, it can be said that it is desirable to determine the positive or negative of the one with the larger absolute value.

<Fourth embodiment>
FIG. 15 is a schematic diagram illustrating a fourth embodiment of the electronic device 100. The present embodiment is characterized in that the magnetic sensors A and B and the magnetic sensors C and D are distributed and integrated in separate magnetic sensors IC40AB and 40CD while being based on the third embodiment (FIG. 7). Have Therefore, the same components as those in the third embodiment are denoted by the same reference numerals as those in FIG. 7, and redundant descriptions are omitted. In the following, the characteristic portions of the fourth embodiment will be mainly described.

  As shown in the drawing, the magnetic sensor IC 40AB in which the magnetic sensors A and B are integrated is mounted in the vicinity of the left end of the paper surface on the first mounting surface of the printed circuit board PCB. On the other hand, the magnetic sensor IC 40CD in which the magnetic sensors C and D are integrated is mounted in the vicinity of the right end of the paper surface on the first mounting surface of the printed circuit board PCB.

  That is, the magnetic sensor IC 40AB and the magnetic sensor IC 40CD are mounted on the same mounting surface of the printed circuit board PCB at a position where the distance between them is as much as possible.

  By adopting such a configuration, the distance between the sensors (= the distance between the magnetic sensors A and B and the magnetic sensors C and D) can be increased as compared with the third embodiment (FIG. 7). . Therefore, since the output difference (= A−D) between the magnetic sensors A and D and the output difference (= C−B) between the magnetic sensors B and C are increased, even if the cover 20 is misaligned, It becomes possible to correctly determine the displacement state of the main body 10 and the cover 20.

<Other variations>
In the above-described embodiment, the description has been given by taking so-called 2in1PC as an application example, but the application target of the invention disclosed in the present specification is not limited to this, and for example, a smartphone or It can also be applied as a means for determining the open / closed state of a notebook-type cover that can be attached to and detached from the tablet, or as a means for determining the open / closed state of a clamshell type electronic device (such as a notebook PC or portable game device) Is preferred.

  Various technical features disclosed in the present specification can be variously modified within the scope of the technical creation in addition to the above-described embodiment. That is, the above-described embodiment is to be considered in all respects as illustrative and not restrictive, and the technical scope of the present invention is indicated not by the description of the above-described embodiment but by the scope of the claims. It should be understood that all modifications that fall within the meaning and range equivalent to the terms of the claims are included.

  The invention disclosed in the present specification can be used for electronic devices such as smartphones, tablets, and notebook PCs.

100 Electronic device 10 Main body (first housing)
10a 1st main surface 10b 2nd main surface 20 Cover (2nd housing | casing)
20a 1st main surface 20b 2nd main surface 30 Connection part 40, 40A, 40B, 40AB, 40CD Magnetic sensor IC (magnetic detection part)
41A, 41B Dynamic offset canceller 42A, 42B Amplifier 43A, 43B AD converter 44 Logic unit 45 Interface unit 46 Regulator 47 Power-on reset unit 48 Oscillator 50 Magnet 60 Microcomputer (control unit)
A, B, C, D Magnetic sensor PCB Printed circuit board

Claims (10)

A first housing and a second housing that are displaceable between a first state in which the respective first main surfaces face each other and a second state in which the respective second main surfaces face each other;
A magnetic detector provided in the first housing;
A magnet provided in the second housing;
A control unit for determining the first state and the second state based on an output of the magnetic detection unit;
Have
The magnet is disposed such that the magnetization direction thereof is orthogonal to the first main surface and the second main surface of the second casing,
The magnetic detection unit includes a first magnetic sensor and a second magnetic sensor disposed along a normal direction of the first main surface and the second main surface of the first housing.
An electronic device characterized by that.   The electronic device according to claim 1, wherein the control unit determines the first state and the second state by comparing outputs of the first magnetic sensor and the second magnetic sensor.   3. The electronic apparatus according to claim 1, wherein the first magnetic sensor and the second magnetic sensor are both integrated in a single magnetic sensor IC. The first magnetic sensor is integrated in a first magnetic sensor IC,
The second magnetic sensor is integrated in a second magnetic sensor IC,
The first magnetic sensor IC is mounted on a first mounting surface of a printed circuit board,
The second magnetic sensor IC is mounted on a second mounting surface of the printed circuit board;
The electronic device according to claim 1, wherein the electronic device is an electronic device. The magnetic detection unit further includes a third magnetic sensor and a fourth magnetic sensor disposed along a normal direction of the first main surface and the second main surface of the first casing,
The third magnetic sensor is disposed on the same plane as the first magnetic sensor,
The fourth magnetic sensor is disposed on the same plane as the second magnetic sensor.
The electronic device according to claim 1.   The control unit determines the positive or negative of the larger absolute value of the difference output of the first magnetic sensor and the fourth magnetic sensor and the difference output of the second magnetic sensor and the third magnetic sensor. The electronic apparatus according to claim 5, wherein the electronic apparatus determines a first state and the second state.   6. The first magnetic sensor, the second magnetic sensor, the third magnetic sensor, and the fourth magnetic sensor are all integrated in a single magnetic sensor IC. The electronic device according to claim 6. The first magnetic sensor and the second magnetic sensor are both integrated in a first magnetic sensor IC,
The third magnetic sensor and the fourth magnetic sensor are both integrated in the second magnetic sensor IC,
The first magnetic sensor IC and the second magnetic sensor IC are both mounted on the same mounting surface of the printed circuit board.
The electronic device according to claim 5, wherein the electronic device is an electronic device. A display unit provided on the first main surface of the first housing;
An operation unit provided on the first main surface of the second housing;
Further comprising
The said control part makes the said electronic device a dormant state when discriminating the said 1st state, and makes the said operation part an invalid state when discriminating the said 2nd state. 9. The electronic device according to any one of 8.   The electronic device according to claim 1, wherein the first housing and the second housing are detachable from each other.